Contrail is a concept bicycle device that attaches above the wheel of a bike and covers the bicycle wheel with a layer of chalk. The chalk then creates a trail or mark on the surface of the road, turning the bike into a sort of large drawing utensil. The concept, developed by Pepin Gelardi of Studio Gelardi focuses around the idea of safety in numbers. By using this device, bicyclists will have a clearer path on which to ride safely and out of the way of vehicular traffic. At the same time, as more bicyclists using the Contrail go over a line created by a cyclist before them, the line gets brighter allowing drivers to clearly see a marked bike path where there might be none. It’s sort of similar to what happens when a dirt path appears in a grassy field after lots of people have taken the same shortcut over a period of time.

Below are two images of what the Contrail would look like in production. The first image shows a cross-section of the unit and how it works and the second image is an early production model.

I’m not too sure about the whole “safety” part of this concept, but I do think the Contrail is a nice way to visually enhance city streets. Imagine seeing colorful lines all over the pavement instead of just regular black or grey asphalt. I’d like that very much!

I’d like to extend this great idea – for me, part of the problem of commuting in LA is that a lot of the bike paths on major roads are in disrepair. It’s as if the city fixes the road good enough for cars, but when they get to the edges where the bike paths are, the attitude is “eh, good enough, screw it.” It’s so bad that I’m expecting someone will crash and sue the city for failure to maintain safe streets.

Anyway, I’d love to see a device that would be able to mark road hazards while in motion on your bike. It’d be something triggered by going over a big bump or pothole, perhaps by dumping chalk on the spot.

I’m for anything that raises awareness of cyclists and makes the streets safer for them.

Wow! What an excellent way for cyclists to show their continued disrespect for road users by effectively applying graffiti to the road. Temporary as it may be it’s still visual pollution, i.e. vandalism.

@ Dan.
“but when they get to the edges where the bike paths are, the attitude is “eh, good enough, screw it.”
Fair comment. When cyclists start paying to use the road that car owners pay to use they should get their bike paths fixed.

This isn’t trolling. It’s pointing out indisputable facts.
Now let’s see all the cyclists respond like offended infants..

The majority of interstate-highway funding comes from gasoline taxes. So yes, car drivers are paying for the highways where bicycles are not allowed to go.

The majority of local road funding, however, comes from property taxes. So I guess you should take up your crusade against renters, since they are the ones getting a free ride on our streets by not paying property taxes.

Cyclists do not have insurance services as car owners. that’s bad; cyclists pay taxes like every other citizen; cyclists do not polute (except when they eat bad food, if you know what I mean); cyclists do not hurt people, so no victim is treated to a hospital from tax money; cyclists are ignored by motorists in traffic, due to their low speed, and treated as they are “blocking” traffic, lol. Cyclists breath all shit exhausted by the motorists, also the pedestrians breath the same shit.

So, Mr EvilGod, who has respect and who doesn’t ? Now go back to your video games and shut up.

@evilgod
agreed with the disrespect/visual polution remark. However, the taxes remark just sounds like you’re carrying a grudge against cyclist. Why don’t you find yourself a hobby, & leave cyclists alone?

While it may look cool and give an indication of the general flow, it may also lead people to treating it as a cycling lane. This has the potential to be counter productive in terms of safety.

Cycling to work daily leads to one developing a natural flow with the road, learn it in a way people in cars don’t experience. Any time one is venturing into a new area they should get a feel for the road before assuming it is the same as any other.

@EvilGod
Where might I find more information about this payment all of the car owners have been making to directly benefit our roads? After having driven a car for many years I must owe a small fortune.

I don’t know about where you you live but most countries charge either vehicle registration fees or some other sort of tax that as far as I know no cyclists ever have to pay. Who do you think is paying for the building and maintenance of bikeways and bike lanes? Cyclists? Not likely.
Read http://betterthangod.wordpress.com/2005/08/18/bloody-cyclists/ and get another perspective.
Cyclists, like most people, either never think about how what they do affects others or simply don’t care. The worst thing about most humans is there lack of consideration for others. in this case a few cyclists expect respect and consideration from drivers but never respect or consider the motorists in return.

as far as I know no cyclists ever have to pay
You make the assumption that all cyclists do not own cars. Your assumption is false.

Who do you think is paying for the building and maintenance of bikeways and bike lanes?
I know that all property owners are paying for these services. There’s lots of services paid for by my taxes that I don’t want or use. But since I am considerate of others I don’t let it bother me.

errr, You might want to look at what’s coming out of your car’s tailpipes before getting on your high horse about some chalk dust on the road!!!
What about repecting everyone’s right not to breath your exhaust fumes!!

Ah, a stupid evil god. Driving makes you stupid. Cyclists choose a method of transport that (almost) cannot kill anyone else. Drivers do not. Which shows more consideration? Car drivers have this elaborate collection of safety rituals, that still don’t make cars as safe for other people as bicycles already are.

The registration fees pay the salaries of the people who collect the registration fees. In the US, at least, towns pay for the maintenance of roads in towns, and this maintenance is mostly funded by property taxes and subsidies from the state, who in turn gets most of their money from income taxes (this state, at least). Oddly enough, cyclists pay property taxes, cyclists pay income taxes.

I don’t know if you had noticed or not, but alcohol taxes fund bars, nor do cigarette taxes subsidize smoking. Where on earth did you get the idea that gasoline taxes were intended to subsidize driving?

Absolutely great…! mmm… Can the chalk get through the brisles of that brush pretty easy? … if not, then solid chalk can be used so that, with a little spring perhaps it can be pressed against the felt brush to be applied to the wheel… Great concept… great idea… wonderfull applications! Let me know what the challenges are please… I would love to work it out further =)

This is such a cool idea! I’ve been waiting now for months! This needs to go into production, but i can’t wait anymore. I would happily take a prototype.
You know once someone seen one chalk trail, they would want to know what, why, and where do I get one? London needs this and so do I. Send me one and i will plaster it all over the London city roads, every day on my way to work!!